Just finished reading Dawn of the Dinosaurs: Life in the Triassic* by Nicholas Fraser, Illustrated by Douglas Henderson. As you might guess from the title, this book contains a lot of what is currently known or surmised about the era, along with some really good illustrations (for the most part - the shorter tailed therapsids and reptiles look a tad ungainly for live animals which must, after all, make sense in their own lifetimes. But then so does a rhinoceros in a still picture.) Starting with the catastrophic end of the Permian period, and the drifting together of all of the continents into the supercontinent Pangaea, and ending as Pangaea broke apart again into Gondwanaland and Laurasia, the Triassic saw an explosion of different forms, including some quite modern looking insects, land-dwelling bipedal crocodilians (who probably looked much like their later distant relatives, the therapod dinosaurs), therapsids (sometimes called "mammal-like reptiles", though to be honest they were neither), conifers, ferns, more ferns, even more ferns (especially at the beginning - they were one of the earliest plants to take advantage of all the room left by the Permian die off, just as they tend to be the first colonizers of burned-over places today), and a lot of other things. Yes, including dinosaurs, who start coming in around the late Triassic (the period is divided into three parts, hence the name.)

I recommend this book with a caveat; if you're totally unfamiliar with biology in general or paleontology in particular this is probably not the book to start with. Otherwise, though, I managed just fine with a 37-year-old Bio degree and various readings since. That and by reading the appendix first which contains info which you are going to need and probably won't have unless you're very knowledgeable recent biostratigraphy, tetrapod anatomy etc. (You can also look a lot of this stuff up on Wikipedia.) Otherwise, if you can handle sentences along the lines of: "Practically all parareptiles exhibit an anapsid (lacking openings) temporal region. Although some authors argue that they are really a paraphyletic assemblage and really nothing more than an odd assortment of primitive 'reptiles', others argue that pareiasaurs and procolophonids really do comprise a monophyletic group." you should do fine. And it really is an interesting book.

*Recommended on a paleo blog of which, alas, I forget the author, and Google keeps landing me in the swamp. I'll edit this post and add it when I can find it. At the very least, I owe him for warning me to read the appendix first. :)